Variable cosmological constant notion has led to a rich structure of phase transitions and critical phenomena. Indeed, in the recent years, thermodynamics and phase transition properties of the black holes in AdS space have been discussed in many studies [1]}, [2]}, [3]}, [4]}, [5]}, [6]}, [7]}, [8]}, [9]}, [10]}, [11]}, [12]}, [13]}, [14]}, [15]}, [16]}, [17]}, [18]}.
